- 0.11.0.0 * Support for IPv6 in the built-in server, client and tests (by agentm). This can cause issues on backends that do not enable IPv6. For more information and a workaround, see this issue: <https://github.com/jaspervdj/websockets/issues/140#issuecomment-296732964>. * Faster masking (by Dmitry Ivanov) * Support for `permessage-deflate` extension (by Marcin Tolysz) * Strict unicode checking and proper extension mechanism